Bank of America's $4.1bn (€2.8bn) offer for Countrywide Financial was thrown into doubt yesterday when a large shareholder in the biggest US mortgage lender said it would vote against the deal.

SRM Global Fund, the Monaco-based hedge fund that has become the biggest shareholder in Northern Rock and has led a fight against British government plans for the future of the stricken UK home lender - said the offer "considerably undervalued" Countrywide.